Relay recorder



M DEN HERTOG RELAY RECORDER Filed ept. 1. 1954 Inve t ney United States Patent RELAY RECORDER Martinus den Hertog, Antwerp, Belgium, assignor to International Standard Electric Corporation, New York, N.Y., a corporation of Delaware Application September 1, 1954, Serial No. 453,594

Claims priority, application Netherlands December 4, 1953 6 Claims. (Cl. 317-137) The invention relates to a relay recorder and more particularly to one in which a single relay can be operated at a time in response to a particular signal corresponding to that relay. Such recorders can be divided into three types: those using as many inputs as there are relays, those using a single input to which a succession of time spaced signals can be applied to cause the operation of a particular relay, and those with a single input to which single but different signals can be applied, each signal causing a different relay to be energized. Combinations of these principles are also possible.

The relay recorder in accordance with the invention is of the third type and the different signals, each of which corresponds to the operation of a particular relay, are obtained by using different potentials applied to the single input terminal, a ground return being assumed. When operating the recorder from another or distant circuit, this scheme has the advantages that only a single lead is required and that the application of only one signal is sufficient to energize the corresponding relay.

The object of the invention is to provide a relay recorder comprising two or more relays, any of which can be operated singly to characterize a particular input potential and which does not necessitate any electromechanical interconnections between the various relays.

In accordance with a first characteristic of the invention, a relay recorder comprises two relays and an input lead, an operating impedance of each of the first and the second relays being connected between the input lead and a first and a second DC. potential source respectively, these connections including rectifiers to avoid a flow of current through these impedances in the absence of an input potential being applied to said lead, a second operating impedance of the first relay being coupled to the operating impedance of the second relay, whereby the application to said lead of a first input potential can result in a flow of current through the first operating impedance of the first relay and in the operation thereof, while the application to said lead of a second input potential can result in a flow of current through all operating irnpedances but so as to cause the operation of the second relay only.

In accordance with a second characteristic of the invention, a relay recorder comprises n(n 2) relays and an input lead. n distinct first DC. potential sources are provided together with 11-1 distinct second D.C. potential sources, potential values of the first sources being alternated with those of the second. Every two consecutive first and second sources are each respectively connected via a first operating impedance of a corresponding relay and via an individual rectifier to a particular point, there being n points altogether which are each connected to the input lead via an individual resistance and said first operating impedances or said individual resistances being also serially associated with an individual rectifier. All rectifiers are similarly poled with respect to the DC. potential sources. Each relay, except the one corresponding only to a particular first source, has a second operating impedance coupled to the first operating impedance of the relay corresponding to the next first source according to potential values, whereby the application of an input potential to said lead respectively results in all rectifiers leading to first and second potential sources which are either all lower or higher than said input potential being made conductive and in all rectifiers leading to first and second. potential sources which are either all higher or lower than said input potential remaining non-conductive, thereby causing the operation of that single relay for which current flows in the first operating impedance only.

In accordance with a further characteristic of the invention, two relay recorders each using two relays and of the type described above, are associated with their input leads combined, the first DC. potential source for the first recorder being used in common for the second recorder and the rectifiers of the first recorder being all poled in an opposite way with respect to their respective sources from all rectifiers of the second recorder, whereby any one out of the four relays can be operated singly in response to the application of a corresponding input potential to said common lead.

In accordance with a further characteristic of the invention, two relay recorders each comprising an equal number of n relays, greater than two, and as described above, are associated with their input leads combined. One of the first potential sources is used in common for both recorders. All the remaining first and second DC. potential sources for the first recorder are higher than the common first D.C. potential source, whereas all the remaining first and second potential sources for the sec ond recorder are lower than the common first source. The point corresponding to a particular pair of first and second potential sources or to a particular first potential source in the first recorder, is commoned to the point in the second recorder which corresponds to the particular pair of first and second potential sources or to a particular first potential source having symmetric rank with respect to the common first potential source and there being n such common points each connected via an individual resistance to said lead. The rectifiers of the first recorders are all poled in an opposite way with respect to their respective sources from all rectifiers of the second recorder, whereby any one out of the 2 n relays can be operated singly in response to the application of a corresponding input potential to said lead.

In accordance with a further characteristic of the invention, the relays are of the electro-magnetic type, the first and second operating impedances are constituted by relay windings and flow of currents in both windings of any relay results in opposite and equal ampere-turns being produced to prevent the operation of the relay.

The above mentioned and other objects and characteristics of the invention will be better understood in relation to the following description of various embodiments to be read in conjunction with the appended drawings which represent:

Fig. 1, an embodiment of a two-relay recorder;

Fig. 2, a first embodiment of a multi-relay recorder;

Fig. 3, a second embodiment of a multi-relay recorder;

Pig. 4, a third embodiment of a multi-relay recorder;

Fig. 5, a first embodiment of a four-relay recorder;

Fig. 6, a second embodiment of a four-relay recorder.

Referring to Fig. l, the right-hand winding of relay S is connected between the input terminal T and one pole of a DC. potential source V the other pole of which is not shown and is connected to ground. The winding of relay S is connected in series with a rectifier G between the input terminal T and one pole of a DC. potential source V the other pole of which is not shown and is connected to ground. The potential of V is higher than that of V whereby the rectifier G poled as shown, normally prevents a flow of current through the windings of relays S and S Relay S has a second winding .which is directly in shunt on the winding of S If a suitable potential, not higher than V is applied to terminal T, relay S can be operated, while relay S remains non-energized. If a potential higher than V is applied to terminal T, relay S can be operated, as rectifier G is now conductive. If this last potential is called V the resistances of the right and left-hand windings of relay S are respectively labelled a and 17 while the respective number of turns for the windings of this relay are p and q then, provided that relay S will remain non-energized if its windings are oppositely wound.

, If one tries to generalize the arrangement shown in Fig. 1 by using more than two relays and by providing all relays except the last with two windings, the second of which will be in parallel with the first winding of the next relay, while each successive relay is biassed to a higher potential than the previous one, one finds that it will be impossible to operate only one relay at a time in response to a particular potential at terminal T. For example, if three relays are used and if V, is the potential applied at terminal T which is sufiiciently high to cause current to flow through the winding of the third relay and the operation of the latter, the condition for the non-operation of relay S at that time is Since both the Equations 1 and 2 must be satisfied simultaneously, the desired result cannot be obtained, since the simultaneous solution of these two equations implies that either V should be equal to V or V should be equal to V which conditions are both in contradiction with the principle of the arrangement.

Fig. 2 shows a way to overcome this and the first three relays of a multi-relay recorder are shown. The righthand winding of relay S is still connected between the input terminal T and source V but in series with a resistance R The junction point of R with the righthand winding of S is connected to an additional source V through a rectifier G' All relays are connected in a similar manner and the potentials of the various sources are such that Each relay except the last (not shown) is still provided with a second winding which is directly in parallel with the first winding of the next relay, as shown. The rectifiers such as G',, G G' G G' permit the decoupling of the various sources, so that in the absence of any potential at terminal T, no energy will be delivered to the arrangement. When a suitable potential, not greater than V is applied to terminal T, relay S can be energized, while the remaining relays remain at rest. When a suitable potential higher than V' but not greater than V is applied to terminal T, relay S can be energized, while the further relays down the chain, starting with S will be without current and therefore at rest. Both the left-hand and the right-hand windings of relay S will pass current, and, since both the rectifiers G and G are now conductive, the potentials at the bottom ends of the resistances R and R will be respectively clamped to V and V irrespective of the exact value of the potential at the input terminal T. This means that the relation should be satisfied in order that the currents in the two windings of relay S should be equal, and therefore, since the windings are oppositely wound, relay S will remain non-operated.

When a potential is higher than V';; but not greater than V the biassing potential for the right-hand winding of relay 5.; (not shown), is applied at terminal T, relay 8;, will be operated, but the potential dilferences across the left-hand and the right-hand windings of relay S will remain respectively equal to Vg-Vz and V V since rectifiers 6' and G; are still conductive and perform their clamping action. This means that relay S will remain at rest for all potentials at terminal T except those between V and V The same reasoning is, of course, applicable for all relays except the last which need only have a single winding, whereby the arrangement permits the operation of one relay at a time in accordance with the value of the input potential at terminal T. All the relays except the last can be made identical with the same number of turns for each of their windings and the same resistances for those. In such a case, when applying Equation 4 to the various two-winding relays, one obtains:

where V represents the equal amount by which the potentials from the sources such as V -.--V V .V V' V differ. Although this is not absolutely es sential, the steps between the sources, such as V Y V V' can also be made equal to V Preferably also, the various input potentials designed to operate a particular relay will be made equal to V V Considering, for example, that the input potential at terminal T is V this will ensure that rectifier G is made conductive, whereby a potential V' V is applied across the right-hand winding of 8,, while the right-hand winding of relay 5;; cannot pass current independently of the action of the rectifier G since the potentials at its two ends are equal.

Instead of applying different input potentials at terminal T, one can apply the same potential V in all cases but each time through a series resistance having a particular value. If using such an arrangement, one desires to obtain potentials such as V V at the input terminal T, the series resistance (not shown) R which corresponds to the operation of relay S will be given by:

where n is the total number of relays. The resistances such as R';, R R' can be chosen in any desired way, for example so as to obtain the best discrimination for these series resistances (not shown), each of which corresponds to the operation of a particular relay and so as to minimize power consumption.

Although both the embodiments of Fig. 1 and Fig. 2 show that the left-hand winding of each relay except the last is connected in parallel with the right-hand winding of the next relay, this is by no means essential and it is merely necessary that such windings should be coupled together.

For example, Fig. 3 shows an arrangement similar to that of Fig. 2 but in which the left-hand winding of each relay except the last is connected in series with the righthand winding of the next relay. In such a case,'however, Equation 4 becomes:

but the principle of the arrangement remains the same. Fig. 4 shows how two relay recorders of the type shown in Fig. 2 can be associated to produce a more efficient arrangement. The various potential sources satisfy the relation V'31 V31 V'21 V21 V'11 V1 but while the rectifiers G G G 6' have their cathodes directed towards their respective sources, the rectifiers such as G G' G G22, have their anodes connected towards their respective sources. Source V is used in common for both the relays S and S and the relays such as S and S are connected in pairs through a common resistance, such as R to the common input terminal T. The arrangement functions in the same way as that shown in Fig. 2. For example, if a potential V is applied to terminal T, only relay S will be operated, since all rectifiers except G and G are non-conductive. The arrangement has, however, the advantage of using half the number of resistances than the number required according to the scheme of Fig. 2. Two potential sources can be spared and two single-winding relays instead of one can be used. Further, if the various potentials to be applied at the input terminal T are obtained from only two different fixed potentials, one which is greater than all the biassing sources and one which is smaller than all the biassing sources, only half the number of series resistances to obtain the required potentials at the input terminal T need be provided, since the same series resistance can be used to provide a potential, such as V at terminal T from the highest of the two fixed sources, or to provide a potential V at the input terminal T from the lowest of the two fixed potential sources. Less series resistances being needed, it will also be easier to obtain the required discrimination between them.

Fig. 5 shows that two relay recorders of the type shown in Fig. 1 can also be associated in the same way as two recorders of the type shown in Fig. 2 were associated to produce the circuit of Fig. 4. This ararngernent favourably compares with a fur-relay recorder of the type shown in Fig. 2 since the latter would require three double-winding relays, one single-winding relay, four resistances, six rectifiers and seven biassing sources, whereas the circuit of Fig. 5 only necessitates two double-winding relays, two single-winding relays, four rectifiers and three biassing sources.

The circuit of Fig. 5 can also be operated from two fixed potential sources (not shown) in series with one out of two different resistances. In all cases, one of these resistances may be replaced by a short-circuit.

If it is preferred to use more relay windings, it is to be remarked that in all cases, each winding connected to a particular biassing source can always be replaced by two windings having equal number of turns, interconnected at one end, having their other ends connected to the two poles of a standard D.C. supply and of such resistive values that the no-load potential at their common end corresponds to that of the particular biassing source. Then, the two windings act as a resistive potentiometer and it they are suitably wound, the fluxes produced in these two windings will be equal and opposite so that the relay armature condition will not be influenced when the recorder is not used.

Such a case is shown by way of example in Fig. 6 which represents a. four-relay recorder of the type shown in Fig. 5 but using series couplings between the windings, as in Fig. 3, and in which the single-winding relays S and S (Fig. 5) are now each provided with two windings (Fig. 6). For each relay, the two windings are joined together at one end while their other ends are respectively connected to the negative pole of a standard telephone exchange battery and to the positive pole thereof which is grounded. Using oppositely wound windings w1th an equal number of turns, the resultant flux will be zero for each relay when no potential is applied to the input terminal T. By suitably selecting the winding resistances, the potentials at the common ends of the windings can be made equal to any desired value. For example, if the left-hand winding of relay S has three times the resistance of the right-hand winding, and if the battery voltage is 48 volts, the cathode of rectifier G will be biassed to 12 volts, while if the right-hand winding of relay S has three times the resistance of its left-hand winding, the anode of rectifier G will be biassed to --36 volts. On the other hand, if the resistances R and R are equal, the cathode of rectifier G and the anode of rectifier G which are interconnected will be biassed to -24 volts. Therefore, by applying ground potential, for example, to the input terminal T, relay S can be energized while relay S can remain at rest by selecting the number of turns of its windings and their resistances so that equal and opposite fluxes are produced. By applying a potential of --12 volts at terminal T, relay S can be made to operate singly, while the application of 36 volts and 48 volts at terminal T will respectively cause the single operation of relay S and relay S The resistances, such as R Which are provided in shunt across each winding of relays S and S are designed to prevent a temporary energization of the relay, such as S when it is desired to operate the relay S Transient conditions are responsible for this and if such a temporary energization of the relays is undesirable and should be avoided, shunt resistances, as shown, will avoid it. These shunt resistances can be of the order of ten to twenty times the resistance of the corresponding winding and the ratio between one resistance and its associated winding should be substantially equal to the ratio between the other resistance and its associated winding.

Although multi-winding relays have been shown, it should be appreciated that the invention is not necessarily limited to those and suitable vacuum tube relays could for example be used provided they are capable of a differential action analogous to that of the relays.

While the principles of the invention have been described above in connection with specific apparatus, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of the invention.

I claim:

1. A relay recorder comprising first and second relays, an input lead, first and second direct current potential sources having a common return, the potential of said first source being lower than that of said second source, a first operating impedance in each of the first and second relays, electrically coupled together, and connected between said input lead and said second direct current potential source, rectifier means connected in series with said first operating impedances poled to avoid a fiow of current through said operating impedances in the absence of an input potential greater than the potential of said second source being applied to said input lead, a second operating impedance in said first relay connected between said input lead and said first direct current potential source, means for causing the operation of said first relay when current flows only through said second operating impedance thereof without current flowing through said first operating impedance thereof and for preventing the operation of said first relay when current flows in the same direction through both operating impedances thereof, and means for causing the operation of said second relay when current flows through the first operating impedance thereof, whereby the application to said input lead of a first input potential different from the potential of said first source but less than the potential of said second source can result in a fiow of current through said second operating impedance of said first relay and in the operation of said first relay, while the application to said input lead of second input potential greater than the potential of said second source can result in a fiow of current through all impedances,

but so as to cause the operation of said second relay fiers of the first recorder all being poled with respect to their respective sources in an opposite manner from all rectifiers of the second recorder, whereby any one out of the four relays can be operated singly in response to the application of a corresponding input potential to said common input lead.

3. A relay recorder arrangement, as claimed in claim 2, in which the relays are of the electro-magnetic type, the first and second operating impedances being constituted by relay windings and in which flow of currents in both windings of any relay results in opposite and equal ampere-turns being produced to prevent the operation of the relay.

4. A relay recorder comprising 21 relays, when n 2, each relay having a first operating impedance, an input lead, 11 distinct first direct current potential sources having a common return, said first sources having successively increasing potential values from the first to the last n-l distinct second direct current potential sources having a common return, said second sources having successively increasing potential values from the first to the last the potential values of said first sources being alternated with those of the second, n circuit points, a plurality of rectifiers, means for connecting every two consecutive first and second sources respectively via a first operating impedance of a corresponding relay and via an individual one of said rectifiers to a particular one of said circuit points, and a plurality of resistances, said circuit points being each connected to said input lead via an individual one of said resistances, a different one of said rectifiers being connected between each of said first operating impedances except that of the first relay and the associated circuit point, all said rectifiers being similarly poled with respect to said direct current sources, each relay except the one corresponding only to a particular first source having a second operating impedance electrically coupled to the first operating impedance of the relay corresponding to the next first source accord ing to potential values, means for causing the operation of each relay when current flows through the first operating impedance without current flowing through the second operating impedance, whereby the application of an input potential to said lead respectively results in all rectifiers leading to first and second potential sources which differ in the same sense from said input potential being made conductive and in all rectifiers leading to first and second potential sources which differ in the opposite sense from said input potential remaining nonconductive, thereby causing the operation of that single relay for which current flows in the first operating impedance only.

5. A relay recorder arrangement comprising two relay recorders, as claimed in claim 4, each comprising n relays, one first direct current potential source being connected in common for both recorders, the input leads being commoned, all the remaining first and second direct current potential sources for the first recorder being higher than said common first direct current potential source, and all the remaining first and second potential sources for the second recorder being lower than said common first source, the point corresponding to a particular pair of first and second potential sources or to a particular first potential source in said first recorder being commoned to the point in said second recorder which corresponds to the particular pair of first and second potential sources or to a particular first potential source having symmetric rank with respect to the common first potential source, there being n such common points, each connected to said input lead via an individual one of the plurality of resistances, the rectifiers of the first recorder being all poled with respect to their respective sources in an opposite manner from all the rectifiers of the sec ond-recorder, whereby any one out of the Zn relays can beoperated singly in response to the application of a corresponding input potential to said lead.

6. A relay recorder arrangement, as claimed in claim 5, in which the relays are of the electro-magnetictype, the first and second operating impedances being cQnsti tuted by relay windings and in which flow of currents in both windings of any relay results in opposite and equal ampere-turns being produced to prevent the operation of the relay.

References Cited in the file of this patent UNITED STATES PATENTS 2,618,706 Kalfaian Nov. 18, 1952 i l l l 

